Shortcuts in full screen view?

Are there any shortcats for zooming etc. in the full screen mode of DevonThink Pro when vieving pdfs? I can’t find anything on this topic from the DevonThink Pro help and I have tried all kinds of combinations with my keyboard but I only manage to scroll the pdf up and down.

The shortcuts of the View menu are of course available. Or just use the contextual menu to zoom in/out.